A basic functionality of a power meter is to measure one or more characteristics of electricity, such as current or voltage. A power meter can be attached to a DIN rail or mounted through a cutout to a door of an electrical panel enclosure for power monitoring equipment. A power meter can conventionally include connectors accessible from a rear of the housing for making connections to the power meter, including power supply, I/O, voltage inputs, current inputs, and communications. In addition, certain base power meter units include an expansion connector accessible through the housing of the base unit for connecting expansion modules that enhance or supplement the standard functionality of the power meter. These expansion modules have a separate housing from the base power meter unit and are connected to the expansion connector through the housing of the base power meter unit. When the base power meter unit has a DIN 96 format, the expansion modules are connected to the back of the power meter unit when it is installed through a door panel. However, when an end-user wishes to install the same power meter unit on a DIN rail and leave open the option for future expansion, the base unit must be rotated on its side 90 degrees to allow expansion modules to be compatible with the DIN rail. As a result, the connectors are rotated on their side, and the safety and informational labels on the housing of the base unit are also rotated on the side, making it difficult to access to the connectors with a screwdriver, for example, or to read the labels.
What is needed is a new solution that does not require the base power meter unit to be rotated when mounted to a DIN rail or through a door panel yet allows the connectors to be easily accessible and the safety and informational text on the labels on the housing of the base unit to be readable right-side up regardless of how the base unit is installed.